Download Genetic and Molecular Evidence - ahs-honorsbio2009-1

Genetic and
Molecular Evidence
19.3
History

Darwin’s biggest
problem in
defending his theory
of evolution was
explaining how
these variations are
inherited.

But with the 20th
century, the study of
genetics has
provided much
support in this topic.
Mutations and Recombination

A genetic variation
could come in the
form of mutation,
and the
recombination of
alleles in sexual
reproducing
eukaryotes.
Mutation is
especially common
in short repeating
nucleotide
sequences, or
microsatellites.
 This happens
because crossing
over, independent
assortment, and
fertilization produce
new combinations of
genes.
DNA Sequences

A kind of mutation that
provides evidence for
evolution are
pseudogenes, or copies
of DNA sequences that
no longer function.
They are not
transcribed or
translated and because
they are not shown,
they are not subjected

they are not subjected
to natural selection and
accumulate mutations
faster than normal
functioning genes.
Close Similarities

Scientists can
 sequences of
compare the amino
homologous genes
acid sequences of
to show relation.
homologous proteins
in species to
compare the
different species.
They can also
compare the
nucleotide